[Molecular analysis of streptococcal pyrogenic exotoxin genes among group A Streptococcus isolates from Japanese patients with pharyngitis and skin infections]

Outbreak of Streptococcus pyogenes emm type 58 in a high dependency unit of a level-1 trauma center of India

Background and Aims:

Group A Streptococcus (GAS) can cause illnesses ranging from self-limited to severe, life-threatening, invasive infections. The objective of the following study was to investigate a suspected Streptococcus pyogenes outbreak in a high dependency unit (HDU) of our trauma center.

Materials and Methods:

All the isolates of beta hemolytic Streptococci were identified by standard microbiological methods, Vitek 2 system and latex agglutination tests. Antimicrobial susceptibility testing was performed as recommended by Clinical Laboratory Standards Institute. Exotoxin genes, including speA, speB, speC, speF, smeZ, ssa, speG, speH, speJ, speL, speM and speI were detected by polymerase chain reaction (PCR). The emm types of isolates of S. pyogenes were determined by sequencing the variable 5’ end of emm gene after amplification by PCR.

Results:

In a 28 bedded poly-trauma ward with a four bedded HDU three out of four patients developed S. pyogenes emm type 58 infection. The strain was macrolide and tetracycline resistant and produced the Streptococcal pyrogenic exotoxins speB, speC, speG, speF and smeZ. Surveillance sampling was done for investigation from patients, health-care workers and environmental samples.

Conclusion:

An outbreak of GAS infections was established caused by the uncommonly reported emm type 58. The outbreak was controlled by prompt treatment, intensive surveillance, feedback and training.

Emergence of uncommon emm types of Streptococcus pyogenes among adult patients in southern Taiwan

BACKGROUND

Streptococcus pyogenes isolated from adult patients during a 12-year period in southern Taiwan were analyzed to estimate the distribution of emm types and their correlation with disease manifestations and patient age.

METHODS

Three hundred thirty-four invasive and noninvasive isolates collected from patients older than 20 years between 1997 and 2008 at National Cheng Kung University Hospital were included for emm typing. A correlation between emm type, disease manifestations, and patient ages was analyzed.

RESULTS

The nine most prevalent types were emm11, emm12, emm4, emm1, Sp9458/VT8, emm81, emm106, emm13, and emm75. Formerly rare emm types, including emm11, emm81, and emm102, emerged dramatically after 2004 in southern Taiwan. Type emm11 was significantly associated with both superficial infections and cellulitis. In addition, types emm13, emm81, and emm106 were more prevalent in patients older than 50 years and significantly associated with specific invasive disease manifestation.

CONCLUSION

These results suggest new emm types (emm11, emm81, and emm102) of S pyogenes were introduced into the adult population in southern Taiwan after 2004. The rarely reported emm types, including emm13, emm81, and emm106, caused invasive diseases more often in adult patients.